As regards keys used in a conventional slim keyboard, each keycap is held and supported by means of a bridge structure, wherein the bridge structure enables the keycap to travel the key travel distance when pressed down. However, the bridge structure is a scissor structure formed by assembling two independent frames. Obviously, the bridge structure is complex and difficult to assemble. The frames may rupture readily during an assembly process. Upon completion of assembly, it is difficult to detect a ruptured frame used in the bridge structure. As a result, conventional slim keyboards with the bridge structure have drawbacks, namely high manufacturing cost and poor quality control.
In view of the aforesaid drawbacks of the bridge structure adopted by conventional slim keyboards, the inventor of the present invention came up with an innovative idea and invented an improved frame for use in a flat key and to substitute for the aforesaid conventional bridge structure.